1. Field of the Invention
The present invention relates generally to telephonic communications, and more particularly to providing universal access to interactive voice response systems.
2. Related Art
Two types of telephone dialing are in use today worldwide: dial pulse (“DP”) and dual-tone multi-frequency (“DTMF”). DP is a signaling standard developed in 1920s to operate automatic telephone switching equipment that requires pulses of electrical current to operate relay-type selector gear. DP pulses are created by breaking the current in the local loop a number of times corresponding to the digit being dialed. The term “DP telephone” is used herein to refer to telephones that can communicate using DP signaling. DP telephones can include, for example, rotary telephones and pushbutton telephones having a keypad. The round dial of the rotary telephone is rotated counterclockwise to the desired digit and released causing a small cam to break the loop the correct number of times. For pushbutton telephones, pulses are created electronically after the desired digit is pressed on the keypad.
The DTMF dialing mode was developed by Bell Laboratories and introduced in the United States in mid-1960s as an alternative to DP. Each of 16 possible DTMF signals is represented by a unique pair of frequencies.
A majority of land line telephones in use today worldwide (60 to 70% by some estimates) cannot dial in DTMF. This is mostly because older type central offices (e.g., step-by-step and crossbar type central offices) within telephone networks do not recognize DTMF signaling in the local loop. DP remains the most common signaling in these countries. Telephone users may also choose to retain DP service when it is less expensive than DTMF service.
Unfortunately, this vast segment of the worldwide telephone market is unable to access the many and varied interactive voice response (IVR) systems, enhanced services, and other call processing applications that have become prevalent in many countries. The majority of these systems are designed to receive only DTMF signals from callers.
As a result, businesses and residential users are unable to access many efficiency-enhancing IVR applications such as, for example, voice mail, auto-attendant, information bureaus, automated ordering systems, and telebanking. Telephone companies cannot offer any enhanced high-margin caller services, effectively limiting them to two main sources of revenue: installation/activation fees and monthly charges for basic telephone service. Local telephone companies are also losing money because of the low call completion rate associated with DP service, because only those calls which are successfully connected and followed by conversation are chargeable and thus profit generating. Long distance providers cannot implement widespread pre-paid calling card systems which rely on DTMF signaling. This drastically reduces competition in many countries, driving up rates for long distance and international calls.
Furthermore, travelers overseas experience difficulties accessing their IVR systems at home when visiting countries where DP prevails. Paging companies are limited to using more expensive alphanumeric pagers to provide worldwide coverage, which requires that they also support expensive call centers having numerous operators for receiving requests and manually paging their customers.
A number of different systems have been developed in order to overcome the so-called DTMF barrier. These systems can be grouped into two main categories: systems implemented on the IVR side, and systems implemented on the caller side.
Dial pulse recognition systems are a first IVR-side example. Telephone networks normally do not pass through to the IVR system the actual electrical DP pulses from DP telephones. Rather, the IVR system at best receives audible clicks corresponding to the DP pulses. Two different dial pulse recognition systems have been implemented: pulse detection and pulse-to-DTMF conversion. Both are based on detecting and counting the audible clicks received by the IVR system. Pulse detection systems are implemented on the voice boards installed inside the computers that support the IVR system. Special software detects the incoming audible clicks and passes the results to the IVR application. For example, Dialogic Corporation has implemented pulse detection within their products. Pulse-to-DTMF conversion systems detect the incoming audible clicks and generate an equivalent DTMF signal which is then used by the IVR system. These systems are often implemented as separate equipment, such as personal computer (PC) boards or a separate stand-alone system. For example, Teleliaison, Aerotel Corporation, and Sumihiro Signal Processing have implemented pulse-to-DTMF conversion systems.
However, dial pulse recognition systems suffer from several disadvantages. First, these systems have not proven to be reliably accurate. Both require accurate detection of the audible clicks associated with DP signals, the accuracy of which depends on, for example, the type of central office equipment, noise in the speech path, and the network configuration. Some networks completely filter out the audible clicks, rendering IVR-side dial pulse recognition systems completely useless. Furthermore, these systems are very expensive (e.g., from $200 to $700 per port). The cost of adding dial pulse recognition can often double the overall cost of an IVR system. These costs are passed along to subscribers in the form of higher rates.
Speech recognition systems are a second IVR-side example. Speech recognition technology allows callers to interact with IVR systems through spoken phrases. The IVR system is equipped with special hardware and/or software that is designed to understand certain voice commands. Speech recognition systems can vary, for example, by the number of words in their vocabulary, by the number of languages supported, and by the sophistication of their speech recognition algorithm. However, speech recognition technology is very expensive (e.g., $1,000+per port), often more than doubling overall system cost. Reliability is also low, given that the accuracy of speech recognition can depend upon, for example, the caller's speaking habits (e.g., accents, voice levels, changes in voice due to sickness), and the network quality (e.g., noise levels).
Different caller-side systems have also be implemented. Portable DTMF tone generators are a first caller-side example system that allow users to access IVR systems using any DP telephone. The user places a call and waits for the IVR system to answer. Once the IVR answers, the user places the generator against the microphone of the handset while keeping the earpiece against her ear, and presses the appropriate buttons on the generator's keypad in response to the IVR spoken instructions. The device generates the appropriate audible DTMF signals which are picked up by the microphone and sent to the IVR system.
However, these portable generators are inconvenient to use. Users must purchase and carry these devices in order to access their IVR services. They also require special training and a level of manual dexterity that significant portions of the population may not possess, such as older users and persons with physical disabilities. For example, in order to achieve reliable results, the user must hold the device properly against the handset and press the correct buttons on what is often a small keypad. Furthermore, these battery-operated devices are usually good for about 2000 calls before the batteries must be changed, leaving open the possibility that the device may “die” at a crucial moment. These devices can be easily damaged, lost or stolen, and are relatively expensive (approximately $20), particularly taking into consideration salary levels in many developing countries (e.g., $100 per month or less).
Telephones capable of switching between dialing modes are a second example of caller-side systems. Some of these telephones can be manually switched between DP and DTMF modes, for example, by pushing a designated button on the telephone's keypad (e.g.,“*”). The caller places the call in DP mode, and then switches to DTMF once the IVR system answers. An example of this type telephone can be found in U.S. Pat. No. 4,731,826 to Daie. However, the caller must purchase a dual-mode phone and must remember to switch modes when accessing IVR services.
Other dual-mode telephones include hardware that recognizes when a call has been connected and switches automatically from DP to DTMF, examples of which can be found in U.S. Pat. No. 5,638,437 to Bettan et al. (“Bettan”), and U.S. Pat. No. 5,369,697 to Murray et al. (“Murray”). These automatic telephones must use some criteria for switching dialing modes. Bettan, for example, switches dialing modes upon detecting a ring back signal. Performance can degrade whenever, as is often the case, generation of ring back signals and ring signals is not synchronized. This frequently occurs where IVR systems are installed behind a private branch exchange (PBX). Here, the IVR might answer the call before the telephone receives the ring back signal. Automatic dual-mode telephones also will not work with IVR applications that require outbound dialing (e.g., message notification).
Still other telephones, such as those described in U.S. Pat. No. 4,119,810 to Marin et al., include a telephone apparatus with automatic dialing and sequential control signaling capabilities. These telephones can support sequential dialing in DP and DTMF under user control, or automatically in a preprogrammed mode. However, in manual mode, the user must still remember to switch from one mode to the next, and the automatic mode is not appropriate for interacting with an IVR system because the callers response will vary according to particular menu options.
Of course, for those areas in which DTMF signaling is already supported by the local telephone company, users must only replace their old DP telephone with a DTMF capable telephone in order to access IVR services. However, the cost of a new telephone, though minimal, can be significant when compared to the average income in many developing countries. Users may also decide to stay with DP service because they do not want to pay extra fees for DTMF service. Sometimes, users are not even aware that DTMF service exists and what it is all about.
For those areas in which DTMF signaling is not yet supported, upgrading the telephone network to accommodate DTMF can be very expensive, and in some cases, may not be possible short of wholesale replacement of the network. The cost of system upgrades can, for example, range from $5 to $10 per subscriber for hardware only, with significant additional labor costs for research, testing and implementation.
Many current systems also do not support outbound dialing features. Outbound dialing refers to those features wherein the IVR system initiates a call to a user. For example, an IVR system that provides voice mail can call to notify a subscriber that a new voice message has been received. However, the majority of IVR-side systems start working only after receiving an incoming ling. During an outbound call from IVR system to subscriber, there will be no incoming ring signal into the IVR system and as a result the IVR-side system will be disabled. On the other hand, existing caller-side systems depend on receiving some control signal, for example ring back, to switch from DP to DMTF mode. But these signals are not received by the caller-side system when the IVR system calls the subscriber.
A need therefore exists for a low-cost, reliable system and method for allowing callers using DP telephone service to access IVR systems.